This invention is concerned with a timepiece bracelet.
According to U.S. Pat. No. 2,979,794 it is already known to provide a securing collar for a bundle of cables which includes a clasp comprising a sleeve defining a passage which extends longitudinally relative to the tongue of the collar to which it is attached and in which there may be inserted the other tongue of the collar, one of the surfaces of this other tongue being provided with teeth extending transversally and cooperating with the teeth of a complementary set provided in the sleeve in a manner to be retained by a ratchet effect on the teeth of the sleeve, this latter being transversally deformable in order to enable release of the ratchet when the collar is opened.
The arrangement of this collar or more precisely, of its clasp, renders it particularly apt to fulfil the purpose for which it was intended, i.e. to hold the cables of a bundle together and to permit moreover release of the collar in the event that the bundle must be changed for one or another reason. It is thus because the collar exhibits relatively small width in a manner such that when the sleeve is laterally deformed to effect opening of the collar, it assumes a form of circular section which enables the disengagement without difficulty of the meshing teeth from one another.
If one attempts to apply the construction principle of this collar to the manufacture of a timepiece bracelet, initially there will appear the tendency to increase the width of the tongues in order to give them the usual dimensions applicable in horology. However, in so doing, one runs up against problems when the bracelet is to be opened (everything else being equal) for when the lateral deformation of the sleeve, which has then a cross-section of width clearly greater than its height, takes place, the sleeve takes on an oval form in locally deforming the edges of the tongue which is introduced therein. Under such conditions the teeth may not be disengaged from one another since the ridges of the teeth are maintained in contact above all at their two ends, i.e. next to the lateral edges of the sleeve. This default is moreover more pronounced to the extent that the bracelet is more tightly secured about the wrist of the user.
Another factor which aggravates further this phenomenon arises from the tendency of the tongues of the bracelet from their own elasticity to spread apart from one another when they are not attached by the clasp. Thereby the teeth are urged to inter-penetrate one another which is favourable for avoiding an undesired opening of the collar but on the other hand does not facilitate this operation when one purposely attempts to effect it. Thus, when the sleeve is laterally deformed for the opening of the bracelet, the teeth continue to be urged in the same sense, i.e. to be hooked into one another.
It will be evident that these defaults of the previously known technique which become manifest when one wishes to apply it to a timepiece bracelet, do not motivate the specialist to employ it for this particular purpose.
The invention however consists precisely in the idea of creating a bracelet for a timepiece, the basic conception thereof being drawn from this previously known technique, which is adapted in a special manner to enable it to be used for this purpose.